Amino styrene derivatives

ABSTRACT

Styrene derivatives of the formula ##STR1## and an electrophotographic photoconductor comprising an electroconductive support material and a photosensitive layer comprising at least one styrene derivatives of the same formula are disclosed, in which Ar represents an unsubstituted of substituted phenyl group or an unsubstituted or substituted styryl group, R represents hydrogen, a lower alkyl group or an unsubstituted or substituted phenyl group, and A is selected from the group consisting of ##STR2## wherein R 1  represents a lower alkyl group or a lower alkoxy group, R 2  and R 3  each represent a lower alkyl group, an aralkyl group, or an unsubstituted or substituted phenyl group.

This is a division of application Ser. No. 07/545,124, filed on Jun. 27,1990, now U.S. Pat. No. 5,072,043, which is a continuation of 07/403,055filed Sep. 5, 1989 and is now abandoned which is a continuation of Ser.No. 06/839,965 filed Mar. 17, 1986 and is now abandoned which is adivisional of Ser. No. 06/646,064 filed Aug. 31, 1984 which has a U.S.Pat. No. 4,603,097.

BACKGROUND OF THE INVENTION

The present invention relates to styrene derivatives and anelectrophotographic photoconductor comprising a photosensitive layercontaining at least one of the styrene derivatives overlayed on anelectroconductive support material.

Conventionally, a variety of inorganic and organic electrophotographicphotoconductors are known. As inorganic photoconductors for use inelectrophotography, there are known types, in which the photoconductivematerial is, for instance, selenium, cadmium-sulfide and zinc oxide. Inan electrophotographic process, a photoconductor is first exposed tocorona charges in the dark, so that the surface of the photoconductor iselectrically charged uniformly. The thus uniformly chargedphotoconductor is then exposed to original light images and the portionsexposed to the original light images selectively becomeelectroconductive so that electric charges dissipate from the exposedportions of the photoconductor, whereby latent electrostatic imagescorresponding to the original light images are formed on the surface ofthe photoconductor. The latent electrostatic images are then developedby the so-called toner which comprises a colorant, such as a dye or apigment, and a binder agent made, for instance, of a polymeric material;thus, visible developed images can be obtained on the photoconductor. Itis necessary that photoconductors for use in electrophotography have atleast the following fundamental properties: (1) chargeability to apredetermined potential in the dark; (2) minimum electric chargedissipation in the dark; and (3) quick dissipation of electric chargesupon exposure to light.

While the above-mentioned inorganic electrophotographic photoconductorshave many advantages over other conventional electrophotographicphotoconductors, at the same time they have several shortcomings fromthe viewpoint of practical use.

For instance, a selenium photoconductor, which is widely used atpresent, has the shortcoming that its production is difficult and,accordingly, its production cost is high. Further, it is difficult towork it into the form of a belt due to its poor flexibility, and it isso vulnerable to heat and mechanical shocks that it must be handled withthe utmost care.

Cadmium sulfide photoconductors and zinc oxide photoconductors areprepared by dispersing cadmium sulfide or zinc oxide in a binder resin.They can be produced inexpensively compared with seleniumphotoconductors and are also used commonly in practice. However, thecadmium sulfide and zinc oxide photoconductors are poor in surfacesmoothness, hardness, tensile strength and wear resistance. Therefore,they are not suitable as photoconductors for use in plain paper copiersin which the photoconductors are used in quick repetition.

Recently, organic electrophotographic photoconductors, which are saidnot to have such shortcomings of the inorganic electrophotographicphotoconductors, have been proposed, and some of them are in factemployed for practical use. Representative examples of such organicelectrophotographic photoconductors are an electrophotographicphotoconductor comprising poly-N-vinylcarbazole and2,4,7-trinitro-fluorene-9-one (U.S. Pat. No. 3,484,237); aphotoconductor in which poly-N-vinylcarbazole is sensitized by apyrylium salt type dyestuff (Japanese Patent Publication No. 48-25658);a photoconductor containing as the main component an organic pigment(Japanese Laid-Open Patent Application No. 47-37543); and aphotoconductor containing as the main component an eutectic crystalinecomplex (Japanese Laid-Open Patent Application No. 47-10735).

Although the above-mentioned organic electrophotographic photoconductorshave many advantages over other conventional electrophotographicphotoconductors, they still have several shortcomings from the viewpointof practical use, in particular, in terms of cost, production,durability and electrophotographic sensitivity.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide styrenederivatives, and an electrophotographic photoconductor or elementcomprising a photosensitive layer containing at least one of the styrenederivatives overlayed on an electroconductive support material, havinghigh photosensitivity, which does not give rise to difficulties inproducing the electrophotographic photoconductor, and which iscomparatively inexpensive and excellent in durability.

The styrene derivatives employed in the present invention arerepresented by the following general formula (I): ##STR3## wherein Arrepresents an unsubstituted or substituted phenyl group, or anunsubstituted or substituted styryl group, R represents hydrogen, alower alkyl group or an unsubstituted or substituted phenyl group, and Arepresents ##STR4## wherein R¹ represents a lower alkyl group or a loweralkoxy group, R² and R³ each represent a lower alkyl group, an aralkylgroup, or an unsubstituted or substituted phenyl group.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an infrared spectrum of2-methyl-4-N,N-diphenylamino-β-phenylstilbene.

FIG. 2 is an infrared spectrum of2-N,N-ditolylamino-5-(β-phenylstyryl)thiophene.

FIG. 3 is an infrared spectrum ofβ-phenylstyryl-4-N,N-diphenylaminonaphthalene.

FIG. 4 is an enlarged schematic cross-sectional view of an embodiment ofan electrophotographic photoconductor according to the presentinvention.

FIG. 5 is an enlarged schematic cross-sectional view of anotherembodiment of an electrophotographic photoconductor according to thepresent invention.

FIG. 6 is an enlarged schematic cross-sectional view of a furtherembodiment of an electrophotographic photoconductor according to thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The electrophotographic photoconductor according to the presentinvention comprises a photosensitive layer which contains at least oneof the styrene derivatives of the above mentioned formula (I), overlayedon an electroconductive support material.

Of the styrene derivatives of the previously described formula (I),stilbene-type derivatives of the following formula (Ia), in which A is##STR5## can be synthesized by reacting a phenyl derivative of formula(IIa) with an aldehyde compound of formula (IIIa): ##STR6## wherein Arrepresents an unsubstituted or substituted phenyl group or anunsubstituted or substituted styryl group, R represents hydrogen, alower alkyl group or an unsubstituted or substituted phenyl group, R¹represents a lower alkyl group or a lower alkoxy group, R² and R³ eachrepresent a lower alkyl group, a lower aralkyl group, or anunsubstituted or substituted phenyl group, ##STR7## wherein Ar and R arerespectively the same as those defined in the formula (Ia), Y representsa triphenylphosphonium group of the formula ##STR8## in which Z.sup.⊖represents a halogen; or a dialkoxyphosphorous group of the formula--P(OR⁴)₂ in which R⁴ represents a lower alkyl group, ##STR9## whereinR¹, R² and R³ are respectively the same as those defined in the formula(Ia).

Preparation of the stilbene-type derivative of the previously describedformula (Ia) will now be explained.

In the preparation, the phenyl derivative of the formula (IIa) can beprepared without difficulty by heating a corresponding halomethylcompound and a trialkylphosphite or triphenylphosphite without using anysolvent or using a solvent, such as toluene, tetrahydrofuran orN,N-dimethylformamide. As the trialkylphosphite, those having alkylgroups with 1 to 4 carbon atoms, in particular, those having methylgroups or ethyl groups are preferable.

The thus prepared phenyl derivative of the formula (IIa) is allowed toreact with the aldehyde compound of the formula (IIIa) in the presenceof a basic catalyst at temperatures ranging from room temperature toabout 100° C.

As the basic catalyst for the above reaction, sodium hydroxide,potassium hydroxide, sodium amide, sodium hydride, and alcoholates suchas sodium methylate and potassium-tert-butoxide, can be employed.

As the reaction solvent, the following can be employed: methanol,ethanol, isopropanol, butanol, 2-methoxyethanol, 1,2-dimethoxyethane,bis(2-methoxyethyl) ether, dioxane, tetrahydrofuran, toluene, xylene,dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone and1,3-dimethyl-2-imidazolidinone.

Of the above solvents, polar solvents, for example,N,N-dimethylformamide and dimethyl sulfoxide are particularly suitablefor this reaction.

The reaction temperature for the above reaction can be set in arelatively wide range, depending upon (i) the stability of the solventemployed in the presence of the basic catalyst, (ii) the reactivities ofthe condensation components, that is, the phenyl derivative of theformula (IIa) and the aldehyde compound of the formula (IIIa), and (iii)the reactivity of the basic catalyst which works as a condensation agentin this reaction. For example, when a polar solvent is employed as thereaction solvent, the reaction temperature is preferably set in therange of from room temperature to about 100° C., more preferably in therange of from room temperature to about 80° C. However, if it is desiredto shorten the reaction time or when a less amount of the reactivecondensation agent is employed, the reaction temperature can be elevatedbeyond the aforementioned range.

In the thus prepared styrene derivative of the formula (Ia), ##STR10##the preferable substituents of the phenyl group in Ar and R are, forexample, an alkyl group such as methyl, ethyl, propyl and butyl; analkoxy group such as methoxy, ethoxy, propoxy and butoxy; a phenoxygroup, a benzyloxy group; halogen such as chlorine and bromine; and thepreferable substituents of the phenyl group in R² and R³ are, forexample, an alkyl group such as methyl, ethyl, propyl, and butyl; analkoxy group such as methoxy, ethoxy, propoxy and butoxy; a thioalkoxygroup such as thiomethoxy and thioethoxy; a thiophenyl group; halogensuch as chlorine and bromine; a dialkylamino group such asdimethylamino, diethylamino, dipropylamino and N-methyl-N-ethylamino;hydroxy group, a carboxy group and ester groups thereof, an acyl group;an aryloxy, group such as phenoxy; an aralkyloxy group such asbenzyloxy; a trifluoromethyl group; a nitro group; and a cyano group.

Preparation of the stilbene-type derivatives of the formula (Ia) willnow be explained in detail by referring to the following examples:

SYNTHESIS EXAMPLE 1

30.40 g (0.1 mol) of diethyl 1,1-diphenylmethylphosphonate and 28.7 g of(0.1 mol) of 2-methyl-4-diphenylaminobenzaldehyde were dissolved in 500ml of N,N-dimethylformamide. To this mixture, 16.8 g (0.15 mol) ofpotassium-tert-butoxide was added with the temperature of the reactionmixture maintained in the range of from 25° C. to 35° C. After theaddition of the potassium-tert-butoxide, the mixture was stirred at roomtemperature for 6 hours and was then diluted with 1 l of water. Powderseparated from the reaction mixture was filtered, washed with water anddried, whereby light yellow powder was obtained. The yield was 37.1 g(85%). The thus obtained light yellow powder was recrystallized from amixed solvent of methyl acetate and ethanol, whereby pure2-methyl-4-N,N-diphenylaminophenylstilbene was obtained. The meltingpoint was 119.5 121.0° C.

An infrared spectrum of the2-methyl-4-N,N-diphenylamino-β-phenylstilbene, taken by use of a KBrpellet, is shown in FIG. 1.

The results of the elemental analysis of the thus obtained2-methyl-4-N,N-diphenylamino-β-phenylstilbene were as follows:

    ______________________________________                                                 % C         % H    % N                                               ______________________________________                                        Found      90.62         6.21   3.23                                          Calculated 90.57         6.23   3.20                                          ______________________________________                                    

The above calculation was based on the formula for2-methyl-4-N,N-diphenylamino-β-phenylstilbene of C₃₃ H₂₇ N.

SYNTHESIS EXAMPLES 2 THROUGH 6

Stilbene-type derivatives listed in Table 1 were prepared by the samemethod as in Synthesis Example 1.

                                      TABLE 1                                     __________________________________________________________________________                                                 Elemental Analysis               Example                               Melting Point                                                                        Found/Calculated                 No.  Stilbene Type Derivatives        (°C.)                                                                         % C    % H  %                    __________________________________________________________________________                                                             N                          ##STR11##                       150.0˜151.0                                                                    89.71˜89.70                                                                    6.39/6.43                                                                          3.85/3.88            3                                                                                   ##STR12##                       Oily Material                                                                        89.61/89.55                                                                          6.69/6.72                                                                          3.69/3.73            4                                                                                   ##STR13##                       111.0˜112.0                                                                    85.79/85.89                                                                          6.39/6.45                                                                          3.51/3.58            5                                                                                   ##STR14##                       Oily Material                                                                        89.48/89.55                                                                          6.70/6.72                                                                          3.64/3.73            6                                                                                   ##STR15##                       156.5˜158.5                                                                    89.81/89.87                                                                          6.49/6.52                                                                          3.52/3.62            __________________________________________________________________________

SYNTHESIS EXAMPLE 7

42.3 g (0.1 mol) of 4-chlorobenzyltriphenylphosphonium chloride and 28.7g (0.1 mol) of 2-methyl-4-N,N-diphenylaminobenzaldehyde were dissolvedin 500 ml of N,N-dimethylformamide. To this mixture, 16.8 g (0.15 mol)of potassium-tert-butoxide was added with the temperature of thereaction mixture maintained in the range of from 25° C. to 35° C. Afterthe addition of the potassium-tert-butoxide, the reaction mixture wasstirred at room temperature for 5 hours and was then diluted with 1 l ofwater. Powder separated from the reaction mixture was filtered, washedwith water and dried, whereby light yellow powder was obtained. Theyield was 38.8 g (98.0%) and the melting point of the product was127.5°˜129.5° C.

Upon recrystallization of the powder from a mixed solvent of toluene andn-hexane in the presence of a small amount of iodine,2-methyl-4-N,N-diphenylamino-4'-chlorostilbene precipitated as lightyellow needle-like crystal. The yield was 30.6 g (77.4%). The meltingpoint of the product was 129.3°˜130.5° C.

The results of the elemental analysis of the thus obtained2-methyl-4-N,N-diphenylamino-4'-chlorostilbene were as follows:

    ______________________________________                                                  % C  % H         % N    Cl %                                        ______________________________________                                        Found       81.72  5.57        3.54 9.00                                      Calculated  81.91  5.60        3.54 8.95                                      ______________________________________                                    

The above calculation was based on the formula for2-methyl-4-N,N-diphenylamino-4'-chlorostilbene of C₂₇ H₂₂ NCl.

In addition to the stilbene-type derivatives described in SynthesisExamples 1 through 7, other stilbene-type derivatives of the formula(Ia), that is, ##STR16## which are also useful in the present invention,are listed in the following Table 2.

                                      TABLE 2                                     __________________________________________________________________________     ##STR17##                                                                     Compound No.                                                                          Ar            R                                                                                     ##STR18##                                                                             R.sup.2      R.sup.3                   __________________________________________________________________________     1                                                                                     ##STR19##    H       2- CH.sub.3                                                                            ##STR20##   C.sub.2 H.sub.5             2                                                                                     ##STR21##    H       2- CH.sub.3                                                                            ##STR22##                                                                                  ##STR23##                  3                                                                                     ##STR24##    H       2- CH.sub.3                                                                            ##STR25##                                                                                  ##STR26##                  4                                                                                     ##STR27##    H       2- CH.sub.3                                                                            ##STR28##                                                                                  ##STR29##                  5                                                                                     ##STR30##    H       2- CH.sub.3                                                                            ##STR31##                                                                                  ##STR32##                  6                                                                                     ##STR33##    H       2- CH.sub.3                                                                            ##STR34##                                                                                  ##STR35##                  7                                                                                     ##STR36##    H       2- CH.sub.3                                                                            ##STR37##                                                                                  ##STR38##                  8                                                                                     ##STR39##    H       2- CH.sub.3                                                                            ##STR40##                                                                                  ##STR41##                  9                                                                                     ##STR42##    H       2- OCH.sub.3                                                                           ##STR43##                                                                                  ##STR44##                 10                                                                                     ##STR45##    H       2- OCH.sub.3                                                                           ##STR46##                                                                                  ##STR47##                 11                                                                                     ##STR48##    H       2- OCH.sub.3                                                                           ##STR49##                                                                                  ##STR50##                 12                                                                                     ##STR51##    H       2- OCH.sub.3                                                                           ##STR52##                                                                                  ##STR53##                 13                                                                                     ##STR54##    H       3- CH.sub.3                                                                            ##STR55##                                                                                  ##STR56##                 14                                                                                     ##STR57##    H       3- CH.sub.3                                                                            ##STR58##                                                                                  ##STR59##                 15                                                                                     ##STR60##    H       3- CH.sub.3                                                                            ##STR61##                                                                                  ##STR62##                 16                                                                                     ##STR63##    H       3- OCH.sub.3                                                                           ##STR64##                                                                                  ##STR65##                 17                                                                                     ##STR66##    H       3- OCH.sub.3                                                                           ##STR67##                                                                                  ##STR68##                 18                                                                                     ##STR69##    H       2- CH.sub.3                                                                            ##STR70##   C.sub.2 H.sub.5            19                                                                                     ##STR71##    H       2- CH.sub.3                                                                            ##STR72##                                                                                  ##STR73##                 20                                                                                     ##STR74##    H       2- CH.sub.3                                                                            ##STR75##                                                                                  ##STR76##                 21                                                                                     ##STR77##    H       2- CH.sub.3                                                                            ##STR78##                                                                                  ##STR79##                 22                                                                                     ##STR80##    H       2- CH.sub.3                                                                            ##STR81##                                                                                  ##STR82##                 23                                                                                     ##STR83##    H       2- CH.sub.3                                                                            ##STR84##                                                                                  ##STR85##                 24                                                                                     ##STR86##    H       2- OCH.sub.3                                                                           ##STR87##                                                                                  ##STR88##                 25                                                                                     ##STR89##    H       2- CH.sub.3                                                                            ##STR90##                                                                                  ##STR91##                 26                                                                                     ##STR92##    H       2- CH.sub.3                                                                            ##STR93##                                                                                  ##STR94##                 27                                                                                     ##STR95##    H       2- CH.sub.3                                                                            ##STR96##                                                                                  ##STR97##                 28                                                                                     ##STR98##    H       2- OCH.sub.3                                                                           ##STR99##                                                                                  ##STR100##                29                                                                                     ##STR101##   H       2- OCH.sub.3                                                                           ##STR102##                                                                                 ##STR103##                30                                                                                     ##STR104##   H       2- OCH.sub.3                                                                           ##STR105##                                                                                 ##STR106##                31                                                                                     ##STR107##   H       3- CH.sub.3                                                                            ##STR108##                                                                                 ##STR109##                32                                                                                     ##STR110##   H       2- CH.sub.3                                                                            ##STR111##  C.sub.2 H.sub.5            33                                                                                     ##STR112##   H       2- CH.sub.3                                                                            ##STR113##                                                                                 ##STR114##                34                                                                                     ##STR115##   H       2- CH.sub.3                                                                            ##STR116##                                                                                 ##STR117##                35                                                                                     ##STR118##   H       2- CH.sub.3                                                                            ##STR119##                                                                                 ##STR120##                36                                                                                     ##STR121##   H       2- CH.sub.3                                                                            ##STR122##                                                                                 ##STR123##                37                                                                                     ##STR124##   H       2- OCH.sub.3                                                                           ##STR125##                                                                                 ##STR126##                38                                                                                     ##STR127##   H       2- OCH.sub.3                                                                           ##STR128##                                                                                 ##STR129##                39                                                                                     ##STR130##   H       2- OCH.sub.3                                                                           ##STR131##                                                                                 ##STR132##                40                                                                                     ##STR133##   H       3- CH.sub.3                                                                            ##STR134##                                                                                 ##STR135##                41                                                                                     ##STR136##   H       2- CH.sub.3                                                                            ##STR137##                                                                                 ##STR138##                42                                                                                     ##STR139##   H       2- CH.sub.3                                                                            ##STR140##                                                                                 ##STR141##                43                                                                                     ##STR142##   H       2- CH.sub.3                                                                            ##STR143##                                                                                 ##STR144##                44                                                                                     ##STR145##   H       2- CH.sub.3                                                                            ##STR146##  CH.sub.3                   45                                                                                     ##STR147##   H       2- CH.sub.3                                                                            ##STR148##                                                                                 ##STR149##                46                                                                                     ##STR150##   H       2- CH.sub.3                                                                            ##STR151##                                                                                 ##STR152##                47                                                                                     ##STR153##   H       2- CH.sub.3                                                                            ##STR154##                                                                                 ##STR155##                48                                                                                     ##STR156##   H       2- CH.sub.3                                                                            ##STR157##                                                                                 ##STR158##                49                                                                                     ##STR159##   H       2- CH.sub.3                                                                            ##STR160##                                                                                 ##STR161##                50                                                                                     ##STR162##   H       2- CH.sub.3                                                                            ##STR163##                                                                                 ##STR164##                51                                                                                     ##STR165##   H       2- CH.sub.3                                                                            ##STR166##                                                                                 ##STR167##                52                                                                                     ##STR168##   H       2- OCH.sub.3                                                                           ##STR169##                                                                                 ##STR170##                53                                                                                     ##STR171##   H       2- OCH.sub.3                                                                           ##STR172##                                                                                 ##STR173##                54                                                                                     ##STR174##   H       2- OCH.sub.3                                                                           ##STR175##                                                                                 ##STR176##                55                                                                                     ##STR177##   H       3- CH.sub.3                                                                            ##STR178##                                                                                 ##STR179##                56                                                                                     ##STR180##   H       3- OCH.sub.3                                                                           ##STR181##                                                                                 ##STR182##                57                                                                                     ##STR183##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR184##  C.sub.2 H.sub.5            58                                                                                     ##STR185##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR186##                                                                                 ##STR187##                59                                                                                     ##STR188##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR189##                                                                                 ##STR190##                60                                                                                     ##STR191##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR192##                                                                                 ##STR193##                61                                                                                     ##STR194##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR195##                                                                                 ##STR196##                62                                                                                     ##STR197##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR198##                                                                                 ##STR199##                63                                                                                     ##STR200##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR201##                                                                                 ##STR202##                64                                                                                     ##STR203##   CH.sub.3                                                                              2- OCH.sub.3                                                                           ##STR204##                                                                                 ##STR205##                65                                                                                     ##STR206##   CH.sub.3                                                                              2- OCH.sub.3                                                                           ##STR207##                                                                                 ##STR208##                66                                                                                     ##STR209##   CH.sub.3                                                                              2- OCH.sub.3                                                                           ##STR210##                                                                                 ##STR211##                67                                                                                     ##STR212##   CH.sub.3                                                                              2- OCH.sub. 3                                                                          ##STR213##                                                                                 ##STR214##                68                                                                                     ##STR215##   CH.sub.3                                                                              3- CH.sub.3                                                                            ##STR216##                                                                                 ##STR217##                69                                                                                     ##STR218##   CH.sub.3                                                                              3- OCH.sub.3                                                                           ##STR219##                                                                                 ##STR220##                70                                                                                     ##STR221##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR222##                                                                                 ##STR223##                71                                                                                     ##STR224##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR225##                                                                                 ##STR226##                72                                                                                     ##STR227##   CH.sub.3                                                                              2- CH.sub.3                                                                            ##STR228##                                                                                 ##STR229##                73                                                                                     ##STR230##                                                                                  ##STR231##                                                                           2- CH.sub.3                                                                            ##STR232##                                                                                 ##STR233##                74                                                                                     ##STR234##                                                                                  ##STR235##                                                                           2- CH.sub.3                                                                            ##STR236##                                                                                 ##STR237##                75                                                                                     ##STR238##                                                                                  ##STR239##                                                                           2- CH.sub.3                                                                            ##STR240##                                                                                 ##STR241##                76                                                                                     ##STR242##                                                                                  ##STR243##                                                                           2- CH.sub.3                                                                            ##STR244##                                                                                 ##STR245##                77                                                                                     ##STR246##                                                                                  ##STR247##                                                                           2- CH.sub.3                                                                            ##STR248##                                                                                 ##STR249##                78                                                                                     ##STR250##                                                                                  ##STR251##                                                                           2- CH.sub.3                                                                            ##STR252##                                                                                 ##STR253##                79                                                                                     ##STR254##                                                                                  ##STR255##                                                                           2- CH.sub.3                                                                            ##STR256##                                                                                 ##STR257##                80                                                                                     ##STR258##                                                                                  ##STR259##                                                                           2- CH.sub.3                                                                            ##STR260##                                                                                 ##STR261##                81                                                                                     ##STR262##                                                                                  ##STR263##                                                                           2- OCH.sub.3                                                                           ##STR264##                                                                                 ##STR265##                82                                                                                     ##STR266##                                                                                  ##STR267##                                                                           2- OCH.sub.3                                                                           ##STR268##                                                                                 ##STR269##                83                                                                                     ##STR270##                                                                                  ##STR271##                                                                           2- OCH.sub.3                                                                           ##STR272##                                                                                 ##STR273##                84                                                                                     ##STR274##                                                                                  ##STR275##                                                                           2- OCH.sub.3                                                                           ##STR276##                                                                                 ##STR277##                85                                                                                     ##STR278##                                                                                  ##STR279##                                                                           2- OCH.sub.3                                                                           ##STR280##                                                                                 ##STR281##                86                                                                                     ##STR282##                                                                                  ##STR283##                                                                           3- CH.sub.3                                                                            ##STR284##                                                                                 ##STR285##                87                                                                                     ##STR286##   H       2- CH.sub.3                                                                            ##STR287##  C.sub.2 H.sub.5            88                                                                                     ##STR288##   H       2- CH.sub.3                                                                            ##STR289##                                                                                 ##STR290##                89                                                                                     ##STR291##   H       2- CH.sub.3                                                                            ##STR292##                                                                                 ##STR293##                90                                                                                     ##STR294##   H       2- CH.sub.3                                                                            ##STR295##                                                                                 ##STR296##                91                                                                                     ##STR297##   H       2- CH.sub.3                                                                            ##STR298##                                                                                 ##STR299##                92                                                                                     ##STR300##   H       2- CH.sub.3                                                                            ##STR301##                                                                                 ##STR302##                93                                                                                     ##STR303##   H       2- OCH.sub.3                                                                           ##STR304##                                                                                 ##STR305##                94                                                                                     ##STR306##   H       2- OCH.sub.3                                                                           ##STR307##                                                                                 ##STR308##                95                                                                                     ##STR309##   H       3- CH.sub.3                                                                            ##STR310##                                                                                 ##STR311##                __________________________________________________________________________

Of the styrene derivatives of the previously described formula (I),thiophene-type derivatives of the following formula (Ib), in which A is##STR312## can be synthesized by reacting a phenyl derivative of formula(IIb) with an aldehyde compound of formula (IIIb) under the sameconditions, using the same reaction solvents and catalysts as in thecase of the stilbene-type derivatives of the formula (Ia). ##STR313##wherein Ar, R, R² and R³ are respectively the same as those defined inthe stilbene-type derivatives of the previously described formula (Ia).That is, Ar represents an unsubstituted or substituted phenyl group oran unsubstituted or substituted styryl group, R represents hydrogen, alower alkyl group or an unsubstituted or substituted phenyl group, R²and R³ each represent a lower alkyl group, a lower aralkyl group or anunsubstituted or substituted phenyl group. ##STR314## wherein Ar and Rare respectively the same as those defined in formula (Ib) and Yrepresents a triphenylphosphonium group of the formula ##STR315## inwhich Z.sup.⊖ represents a halogen, or a dialkylphosphorous group of theformula --PO(OR⁴)₂ in which R⁴ represents a lower alkyl group.##STR316## wherein R² and R³ are respectively the same as those definedin formula (Ib).

Furthermore, the preferable substituents of the phenyl group in Ar, R,R² and R³ are the same as those of the stilbene-type derivatives of thepreviously described formula (Ia).

Preparation of the thiophene-type derivatives of the formula (Ib) willnow be explained in detail by referring to the following examples:

SYNTHESIS EXAMPLE 8

30.4 g (0.1 mol) of diethyl 1,1-diphenylmethylphosphonate and 30.7 g(0.1 mol) of 2-N,N-ditolylamino-5-thiophene aldehyde were dissolved in100 ml of N,N-dimethylformamide. To this mixture, 16.8 g (0.15 mol) ofpotassium tert-butoxide was added with the temperature of the reactionmixture maintained in the range of from 25° C. to 35° C. After theaddition of the potassium-tert-butoxide, the reaction mixture wasstirred at room temperature for 6 hours and was then diluted with 200 mlof water. Powder separated from the reaction mixture was filtered,washed with water and dried, whereby light yellow powder was obtained.The yield was 42.1 g (92%) and the melting point was 155.5°˜157° C. Thethus obtained light yellow powder was recrystallized from a mixedsolvent of ethyl acetate and ethanol, whereby pure2-N,N-ditolylamino-5-(β-phenylstyryl) thiophene was obtained. Themelting point of the product was 157.0°˜158.0° C.

An infrared spectrum of the 2-N,N-ditolylamino-5-(β-phenylstyryl)thiophene, taken by use of a KBr pellet, is shown in FIG. 2.

The results of the elemental analysis of the thus obtained2-N,N-ditolylamino-5-(β-phenylstyryl) thiophene were as follows:

    ______________________________________                                                  % C  % H         % N    % S                                         ______________________________________                                        Found       83.82  5.92        3.07 6.99                                      Calculated  83.98  5.96        3.06 7.01                                      ______________________________________                                    

The above calculation was based on the formula for2-N,N-ditolylamino-5-(β-phenylstyryl) thiophene of C₃₂ H₂₇ NS.

SYNTHESIS EXAMPLES 9 THROUGH 12

Further thiophene-type derivatives as listed in Table 3 were preparedunder the same procedure as in Synthesis Example 8.

                                      TABLE 3                                     __________________________________________________________________________                                                   Elemental Analysis             Example                                 Melting Point                                                                        Found/Calculated               No.  Thiophene Type Derivatives         (°C.)                                                                         % C   % H  %                   __________________________________________________________________________                                                              N                    9                                                                                  ##STR317##                        142.0˜143.0                                                                    81.79/81.84                                                                         6.08/6.09                                                                          3.60/3.67           10                                                                                  ##STR318##                        93.5˜95.0                                                                      81.95/81.97                                                                         6.40/6.38                                                                          3.49/3.54           11                                                                                  ##STR319##                        Oily Material                                                                        81.82/81.97                                                                         6.22/6.38                                                                          3.37/3.54           12                                                                                  ##STR320##                        175.5˜176.5                                                                    82.41/82.50                                                                         6.40/6.19                                                                          3.49/3.44           __________________________________________________________________________

SYNTHESIS EXAMPLE 13

42.3 g (0.1 mol) of 4-chlorobenzyltriphenylphosphonium chloride and 30.7g (0.1 mol) of 2-N,N-dimethylamino-5-thiophene aldehyde were dissolvedin 100 ml of N,N-dimethylformamide. To this mixture, 16.8 g (0.15 mol)of potassium-tert-butoxide was added with the temperature of thereaction mixture maintained in the range of from 25° C. to 35° C. Afterthe addition of the potassium-tert-butoxide, the reaction mixture wasstirred at room temperature for 5 hours and was then diluted with 200 mlof water. Powder separated from the reaction mixture was filtered,washed with water and dried, whereby light yellow powder was obtained.The yield was 40.3 g (97%) and the melting point of the product was142.0°˜143.5° C.

Upon recrystallization of the powder from a mixed solvent of toluene andn-hexane in the presence of a small amount of iodine,2-N,N-ditolylamino-5,4'-chlorostyrylthiophene precipitated as lightyellow needle-like crystal. The yield was 38.2 g (91.8%). The meltingpoint of the product was 143.0°˜143.7° C.

The results of the elemental analysis of the thus obtained2-N,N-ditolylamino-5,4'-chlorostyrylthiophene were as follows:

    ______________________________________                                                  % C  % H         % N    % Cl                                        ______________________________________                                        Found       75.07  5.80        3.24 8.43                                      Calculated  75.07  5.33        3.37 8.52                                      ______________________________________                                    

The above calculation was based on the formula for2-N,N-ditolylamino-5,4'-chlorostyrylthiophene of C₂₆ H₂₂ NSCl.

In addition to the thiophene-type derivatives described in SynthesisExamples 8 through 13, other thiophene-type derivatives of the formula(Ib), that is, ##STR321## which are also suitable for use in the presentinvention, are listed in the following Table 4.

                                      TABLE 4                                     __________________________________________________________________________     ##STR322##                                                                   Compound No.                                                                          Ar              R      R.sup.2      R.sup.3                           __________________________________________________________________________     96                                                                                    ##STR323##     H                                                                                     ##STR324##  CH.sub.3                           97                                                                                    ##STR325##     H                                                                                     ##STR326##                                                                                 ##STR327##                        98                                                                                    ##STR328##     H                                                                                     ##STR329##                                                                                 ##STR330##                        99                                                                                    ##STR331##     H                                                                                     ##STR332##                                                                                 ##STR333##                       100                                                                                    ##STR334##     H                                                                                     ##STR335##                                                                                 ##STR336##                       101                                                                                    ##STR337##     H                                                                                     ##STR338##                                                                                 ##STR339##                       102                                                                                    ##STR340##     H                                                                                     ##STR341##                                                                                 ##STR342##                       103                                                                                    ##STR343##     H                                                                                     ##STR344##                                                                                 ##STR345##                       104                                                                                    ##STR346##     H                                                                                     ##STR347##                                                                                 ##STR348##                       105                                                                                    ##STR349##     H                                                                                     ##STR350##                                                                                 ##STR351##                       106                                                                                    ##STR352##     H                                                                                     ##STR353##  C.sub.2 H.sub.5                   107                                                                                    ##STR354##     H                                                                                     ##STR355##                                                                                 ##STR356##                       108                                                                                    ##STR357##     H                                                                                     ##STR358##                                                                                 ##STR359##                       109                                                                                    ##STR360##     H                                                                                     ##STR361##                                                                                 ##STR362##                       110                                                                                    ##STR363##     H                                                                                     ##STR364##                                                                                 ##STR365##                       111                                                                                    ##STR366##     H                                                                                     ##STR367##                                                                                 ##STR368##                       112                                                                                    ##STR369##     H                                                                                     ##STR370##                                                                                 ##STR371##                       113                                                                                    ##STR372##     H                                                                                     ##STR373##                                                                                 ##STR374##                       114                                                                                    ##STR375##     H                                                                                     ##STR376##                                                                                 ##STR377##                       115                                                                                    ##STR378##     H                                                                                     ##STR379##                                                                                 ##STR380##                       116                                                                                    ##STR381##     CH.sub.3                                                                              ##STR382##  C.sub.2 H.sub.5                   117                                                                                    ##STR383##     CH.sub.3                                                                              ##STR384##                                                                                 ##STR385##                       118                                                                                    ##STR386##     CH.sub.3                                                                              ##STR387##                                                                                 ##STR388##                       119                                                                                    ##STR389##     CH.sub.3                                                                              ##STR390##                                                                                 ##STR391##                       120                                                                                    ##STR392##     CH.sub.3                                                                              ##STR393##                                                                                 ##STR394##                       121                                                                                    ##STR395##     CH.sub.3                                                                              ##STR396##                                                                                 ##STR397##                       122                                                                                    ##STR398##     CH.sub.3                                                                              ##STR399##                                                                                 ##STR400##                       123                                                                                    ##STR401##     CH.sub.3                                                                              ##STR402##                                                                                 ##STR403##                       124                                                                                    ##STR404##                                                                                    ##STR405##                                                                           ##STR406##                                                                                 ##STR407##                       125                                                                                    ##STR408##                                                                                    ##STR409##                                                                           ##STR410##                                                                                 ##STR411##                       126                                                                                    ##STR412##                                                                                    ##STR413##                                                                           ##STR414##                                                                                 ##STR415##                       127                                                                                    ##STR416##                                                                                    ##STR417##                                                                           ##STR418##                                                                                 ##STR419##                       128                                                                                    ##STR420##                                                                                    ##STR421##                                                                           ##STR422##                                                                                 ##STR423##                       129                                                                                    ##STR424##                                                                                    ##STR425##                                                                           ##STR426##                                                                                 ##STR427##                       130                                                                                    ##STR428##                                                                                    ##STR429##                                                                           ##STR430##                                                                                 ##STR431##                       131                                                                                    ##STR432##     H                                                                                     ##STR433##                                                                                 ##STR434##                       132                                                                                    ##STR435##     H                                                                                     ##STR436##                                                                                 ##STR437##                       133                                                                                    ##STR438##     H                                                                                     ##STR439##                                                                                 ##STR440##                       134                                                                                    ##STR441##     H                                                                                     ##STR442##                                                                                 ##STR443##                       135                                                                                    ##STR444##     H                                                                                     ##STR445##                                                                                 ##STR446##                       136                                                                                    ##STR447##     H                                                                                     ##STR448##                                                                                 ##STR449##                       137                                                                                    ##STR450##     H                                                                                     ##STR451##                                                                                 ##STR452##                       138                                                                                    ##STR453##     H                                                                                     ##STR454##                                                                                 ##STR455##                       139                                                                                    ##STR456##     H                                                                                     ##STR457##                                                                                 ##STR458##                       140                                                                                    ##STR459##     H                                                                                     ##STR460##                                                                                 ##STR461##                       141                                                                                    ##STR462##     H                                                                                     ##STR463##                                                                                 ##STR464##                       __________________________________________________________________________

Of the styrene derivatives of the previously described formula (I),naphthalene-type styrene derivatives of the following formula (Ic), inwhich A is ##STR465## can be synthesized by reacting a phenyl derivativeof formula (IIc) with an aldehyde compound of formula (IIIc) under thesame conditions, using the same reaction solvents and catalysts as inthe case of the stilbene-type derivatives of the formula (Ia).##STR466## wherein Ar, R, R² and R³ are respectively the same as thosedefined in the stilbene-type derivatives of the previously describedformula (Ia). That is, Ar represents an unsubstituted or substitutedphenyl group or an unsubstituted or substituted styryl group, Rrepresents hydrogen, a lower alkyl group or an unsubstituted orsubstituted phenyl group, R² and R³ each represent a lower alkyl group,a lower aralkyl group or an unsubstituted or substituted phenyl group.##STR467## wherein Ar and R are respectively the same as those definedin the formula (Ic) and Y represents a triphenylphosphonium group of theformula ##STR468## in which Z.sup.⊖ represents a halogen or adialkylphosphorous group of the formula --PO(OR⁴)₂ in which R⁴represents a lower alkyl group. ##STR469## wherein R² and R³ arerespectively the same as those defined in formula (Ic).

In the above formula (Ic), the substitution position of ##STR470## ispreferably 4- or 5-position of the naphthalene group. The preferablesubstituents of the phenyl group in Ar and R¹ are, for example, an alkylgroup such as methyl, ethyl, propyl and butyl; an alkoxy group such asmethoxy, ethoxy, propoxy and butoxy; a phenoxy group, a benzyloxy group;halogen such as chlorine and bromine; and the preferable substituents ofthe phenyl group in R² and R³ are, for example, an alkyl group such asmethyl, ethyl, propyl and butyl; an alkoxy group such as methoxy,ethoxy, propoxy and butoxty; a thioalkoxy group such as thiomethoxy andthioethoxy; a thiophenyl group; halogen such as chlorine and bromine; adialkylamino group such as dimethylamino, diethylamino, dipropylamino,N-methyl-N-ethylamino; a hydroxy group, a carboxy group and ester groupsthereof; an acyl group; an aryloxy group such as a phenoxy, anaralkyloxy group such as benzyloxy; a trifluoromethyl group, a nitrogroup and a cyano group.

Preparation of the naphthalene-type derivatives of the formula (Ic) willnow be explained in detail by referring to the following examples:

SYNTHESIS EXAMPLE 14

30.4 g (0.1 mol) of diethyl 1,1-diphenylmethylphosphonate and 32.3 g(0.1 mol) of 4-N,N-diphenylaminonaphthaldehyde were dissolved in 100 mlof N,N-dimethylformamide. To this mixture, 16.8 g (0.15 mol) ofpotassium-tert-butoxide was added with the temperature of the reactionmixture maintained in the range of from 25° C. to 35° C. After theaddition of the potassium-tert-butoxide, the reaction mixture wasstirred at room temperature for 8 hours and was then diluted with 200 mlof water. Powder separated from the reaction mixture was filtered,washed with water and dried, whereby light yellow powder was obtained.The yield was 38.9 g (82%). The thus obtained light yellow powder wasrecrystallized from a mixed solvent of methyl acetate and ethanol andwas then washed with methanol, whereby pure1-N,N-diphenylamino-4-(β-phenylstyryl) naphthalene was obtained.

The results of the elemental analysis of the thus obtained1-N,N-diphenylamino-4-(β-phenylstyryl) naphthalene were as follows:

    ______________________________________                                                 % C         % H    % N                                               ______________________________________                                        Found      91.23         5.75   3.01                                          Calculated 91.28         5.76   2.96                                          ______________________________________                                    

The above calculation was based on the formula for of1-N,N-diphenylamino-4-(β-phenylstyryl)naphthalene of C₃₆ H₂₇ N.

An infrared spectrum of the 1-N,N-diphenylamino-4-(β-phenylstyryl)naphthalene (or β-phenylstyryl-4-N,N-diphenylaminonaphthalene), taken byuse of a KBr pellet, is shown in FIG. 3.

SYNTHESIS EXAMPLES 15 THROUGH 20

Further naphthalene-type derivatives as listed in Table 5 were preparedby the same method as in Synthesis Example 1.

                                      TABLE 5                                     __________________________________________________________________________                                                 Elemental Analysis               Example                               Melting Point                                                                        Found/Calculated                 No.  Naphthalene Type Derivatives     (°C.)                                                                         % C    % H  %                    __________________________________________________________________________                                                             N                    15                                                                                  ##STR471##                      148.0˜149.0                                                                    90.62/90.63                                                                          5.85/5.84                                                                          3.45/3.52            16                                                                                  ##STR472##                      157.5˜158.5                                                                    91.37/91.28                                                                          5.64/5.76                                                                          3.07/2.96            17                                                                                  ##STR473##                      103.5˜105.0                                                                    90.32/90.46                                                                          6.00/6.14                                                                          3.41/3.40            18                                                                                  ##STR474##                      153.0˜155.0                                                                    90.62/90.73                                                                          6.01/5.96                                                                          3.30/3.31            19                                                                                  ##STR475##                      143.5˜145.0                                                                    87.01/87.08                                                                          5.85/5.91                                                                          3.29/3.28            20                                                                                  ##STR476##                      157.5˜158.5                                                                    90.37/90.46                                                                          6.10/6.14                                                                          3.42/3.40            __________________________________________________________________________

SYNTHESIS EXAMPLE 21

42.3 g (0.1 mol) of 4-chlorobenzyltriphenylphosphonium chloride and 32.3g (0.1 mol) of 4-N,N-diphenylaminonaphthaldehyde were dissolved in 100ml of N,N-dimethylformamide. To this mixture, 16.8 g (0.15 mol) ofpotassium-tert-butoxide was added with the temperature of the reactionmixture maintained in the range of from 25° C. to 35° C. After theaddition of the potassium-tert-butoxide, the reaction mixture wasstirred at room temperature for 5 hours and was then diluted with 300 mlof water. Powder separated from the reaction mixture was filtered,washed with water and dried, whereby light yellow powder was obtained.The yield was 39.3 g (91%) and the melting point of the product was126.0°˜127.5° C.

Upon recrystallization of the powder from a mixed solvent of toluene andn-hexane in the presence of a small amount of iodine,1-N,N-diphenylamino-4-(4-chlorostyryl) naphthalene precipitated as lightyellow needle-like crystal. The yield was 34.8 g (80.7%). The meltingpoint of the product was 127.0°˜128.5° C.

The results of the elemental analysis of the thus obtained1-N,N-diphenylamino-4-(4-chlorostyryl) naphthalene were as follows:

    ______________________________________                                                  % C  % H         % N    % C                                         ______________________________________                                        Found       83.57  5.11        5.25 8.05                                      Calculated  83.42  5.13        5.24 8.21                                      ______________________________________                                    

The above calculation was based on the formula for1-N,N-diphenylamino-4-(4-chlorostyryl) naphthalene of C₃₀ H₂₂ NCl.

In addition to the naphthalene-type derivatives described in SynthesisExamples 14 through 21, other naphthalene-type derivatives of theformula (Ic), that is, ##STR477## which are also suitable for use in thepresent invention, are listed in the following Table 6.

                                      TABLE 6                                     __________________________________________________________________________     ##STR478##                                                                    Compound No.                                                                          Ar              R                                                                                    ##STR479##                                                                          R.sup.2       R.sup.3                   __________________________________________________________________________    142                                                                                    ##STR480##     H      4                                                                                    ##STR481##   CH.sub.3                   143                                                                                    ##STR482##     H      4                                                                                    ##STR483##                                                                                  ##STR484##                144                                                                                    ##STR485##     H      4                                                                                    ##STR486##                                                                                  ##STR487##                145                                                                                    ##STR488##     H      4                                                                                    ##STR489##                                                                                  ##STR490##                146                                                                                    ##STR491##     H      4                                                                                    ##STR492##                                                                                  ##STR493##                147                                                                                    ##STR494##     CH.sub.3                                                                             4                                                                                    ##STR495##   C.sub.2 H.sub.5            148                                                                                    ##STR496##     CH.sub.3                                                                             4                                                                                    ##STR497##                                                                                  ##STR498##                149                                                                                    ##STR499##     CH.sub.3                                                                             4                                                                                    ##STR500##                                                                                  ##STR501##                150                                                                                    ##STR502##     CH.sub.3                                                                             5                                                                                    ##STR503##                                                                                  ##STR504##                151                                                                                    ##STR505##     CH.sub.3                                                                             4                                                                                    ##STR506##                                                                                  ##STR507##                152                                                                                    ##STR508##     CH.sub.3                                                                             4                                                                                    ##STR509##                                                                                  ##STR510##                153                                                                                    ##STR511##     CH.sub.3                                                                             4                                                                                    ##STR512##                                                                                  ##STR513##                154                                                                                    ##STR514##     CH.sub.3                                                                             4                                                                                    ##STR515##                                                                                  ##STR516##                155                                                                                    ##STR517##     CH.sub.3                                                                             4                                                                                    ##STR518##                                                                                  ##STR519##                156                                                                                    ##STR520##                                                                                    ##STR521##                                                                          4                                                                                    ##STR522##   CH.sub.3                   157                                                                                    ##STR523##                                                                                    ##STR524##                                                                          4                                                                                    ##STR525##   C.sub.2 H.sub.5            158                                                                                    ##STR526##                                                                                    ##STR527##                                                                          4                                                                                    ##STR528##                                                                                  ##STR529##                159                                                                                    ##STR530##                                                                                    ##STR531##                                                                          4                                                                                    ##STR532##                                                                                  ##STR533##                160                                                                                    ##STR534##                                                                                    ##STR535##                                                                          4                                                                                    ##STR536##                                                                                  ##STR537##                161                                                                                    ##STR538##                                                                                    ##STR539##                                                                          4                                                                                    ##STR540##                                                                                  ##STR541##                162                                                                                    ##STR542##                                                                                    ##STR543##                                                                          4                                                                                    ##STR544##                                                                                  ##STR545##                163                                                                                    ##STR546##                                                                                    ##STR547##                                                                          4                                                                                    ##STR548##                                                                                  ##STR549##                164                                                                                    ##STR550##                                                                                    ##STR551##                                                                          4                                                                                    ##STR552##                                                                                  ##STR553##                165                                                                                    ##STR554##                                                                                    ##STR555##                                                                          4                                                                                    ##STR556##                                                                                  ##STR557##                166                                                                                    ##STR558##                                                                                    ##STR559##                                                                          4                                                                                    ##STR560##                                                                                  ##STR561##                167                                                                                    ##STR562##                                                                                    ##STR563##                                                                          4                                                                                    ##STR564##                                                                                  ##STR565##                168                                                                                    ##STR566##                                                                                    ##STR567##                                                                          4                                                                                    ##STR568##                                                                                  ##STR569##                169                                                                                    ##STR570##                                                                                    ##STR571##                                                                          5                                                                                    ##STR572##   C.sub.2 H.sub.5            170                                                                                    ##STR573##                                                                                    ##STR574##                                                                          5                                                                                    ##STR575##                                                                                  ##STR576##                171                                                                                    ##STR577##                                                                                    ##STR578##                                                                          5                                                                                    ##STR579##                                                                                  ##STR580##                172                                                                                    ##STR581##     H      4                                                                                    ##STR582##   C.sub.2 H.sub.5            173                                                                                    ##STR583##     H      4                                                                                    ##STR584##                                                                                  ##STR585##                174                                                                                    ##STR586##     H      4                                                                                    ##STR587##                                                                                  ##STR588##                175                                                                                    ##STR589##     H      4                                                                                    ##STR590##                                                                                  ##STR591##                176                                                                                    ##STR592##     H      4                                                                                    ##STR593##                                                                                  ##STR594##                177                                                                                    ##STR595##     H      4                                                                                    ##STR596##                                                                                  ##STR597##                178                                                                                    ##STR598##     H      4                                                                                    ##STR599##                                                                                  ##STR600##                179                                                                                    ##STR601##     H      4                                                                                    ##STR602##                                                                                  ##STR603##                180                                                                                    ##STR604##     H      4                                                                                    ##STR605##   C.sub.2 H.sub.5            181                                                                                    ##STR606##     H      4                                                                                    ##STR607##   C.sub.2 H.sub.5            182                                                                                    ##STR608##     H      4                                                                                    ##STR609##                                                                                  ##STR610##                183                                                                                    ##STR611##     H      4                                                                                    ##STR612##                                                                                  ##STR613##                184                                                                                    ##STR614##     H      4                                                                                    ##STR615##                                                                                  ##STR616##                185                                                                                    ##STR617##     H      4                                                                                    ##STR618##                                                                                  ##STR619##                186                                                                                    ##STR620##     H      4                                                                                    ##STR621##   C.sub.2 H.sub.5            187                                                                                    ##STR622##     H      4                                                                                    ##STR623##                                                                                  ##STR624##                188                                                                                    ##STR625##     H      4                                                                                    ##STR626##                                                                                  ##STR627##                189                                                                                    ##STR628##     H      4                                                                                    ##STR629##                                                                                  ##STR630##                190                                                                                    ##STR631##     H      4                                                                                    ##STR632##                                                                                  ##STR633##                191                                                                                    ##STR634##     H      4                                                                                    ##STR635##                                                                                  ##STR636##                192                                                                                    ##STR637##     H      4                                                                                    ##STR638##                                                                                  ##STR639##                193                                                                                    ##STR640##     H      5                                                                                    ##STR641##                                                                                  ##STR642##                194                                                                                    ##STR643##     H      4                                                                                    ##STR644##   C.sub.2 H.sub.5            195                                                                                    ##STR645##     H      4                                                                                    ##STR646##                                                                                  ##STR647##                196                                                                                    ##STR648##     H      5                                                                                    ##STR649##                                                                                  ##STR650##                197                                                                                    ##STR651##     H      4                                                                                    ##STR652##                                                                                  ##STR653##                198                                                                                    ##STR654##     H      4                                                                                    ##STR655##                                                                                  ##STR656##                199                                                                                    ##STR657##     H      4                                                                                    ##STR658##                                                                                  ##STR659##                200                                                                                    ##STR660##     H      4                                                                                    ##STR661##                                                                                  ##STR662##                201                                                                                    ##STR663##     H      4                                                                                    ##STR664##                                                                                  ##STR665##                202                                                                                    ##STR666##     H      4                                                                                    ##STR667##   C.sub.2 H.sub.5            203                                                                                    ##STR668##     H      4                                                                                    ##STR669##                                                                                  ##STR670##                204                                                                                    ##STR671##     H      4                                                                                    ##STR672##                                                                                  ##STR673##                205                                                                                    ##STR674##     H      4                                                                                    ##STR675##                                                                                  ##STR676##                206                                                                                    ##STR677##     H      4                                                                                    ##STR678##                                                                                  ##STR679##                __________________________________________________________________________

In the electrophotographic photoconductor according to the presentinvention, at least one styrene derivative of the previously describedformula (I) is contained in the photosensitive layer. Those styrenederivatives can be employed in different ways, for example, as shown inFIG. 4, FIG. 5 and FIG. 6.

In the photoconductor shown in FIG. 4, a photosensitive layer 2a isformed on an electroconductive support material 1, which photosensitivelayer 2a comprises a styrene derivative, a sensitizer dye and a binderagent. In this photoconductor, the styrene derivative works as aphotoconductor material through which charge carriers are generated andtransported. The generation and transportation of charge carrier arenecessary for the light decay of the photoconductor. However, thestyrene derivative itself scarcely absorbs light in the visible lightrange. Therefore, it is necessary to add a sensitizer dye which absorbslight in the visible light range in order to form latent electrostaticimages on the photoconductor by use of visible light.

Referring to FIG. 5, there is shown an enlarged cross-sectional view ofanother embodiment of an electrophotographic photoconductor according tothe present invention.

In the figure, on the electroconductive support material 1, there isformed a photosensitive layer 2b comprising a charge generating material3 dispersed in a charge transporting medium 4 which comprises a styrenederivative and a binder agent. In this embodiment, the combination ofthe styrene derivative and the binder agent (or a plasticizer and abinder agent) constitutes the charge transporting medium 4. The chargegenerating material 3, which is, for example, an inorganic or organicpigment, generates charge carriers The charge transporting medium 4mainly serves to accept the charge carriers generated by the chargegenerating material 3 and to transport those charge carriers.

In this electrophotographic photoconductor, it is a basic requirementthat the light-absorption wavelength regions of the charge generatingmaterial 3 and the styrene derivative not overlap in the visible lightrange This is because, in order that the charge generating material 3light pass through the charge transporting medium 4 and reach thesurface of the charge generating material 3 produce charge carriersefficiently, it is necessary that Since the styrene derivatives of theformula (I) do not substantially absorb light in the visible range, theycan work effectively as charge transporting materials when used incombination with the charge generating material 3 which absorbs thelight in the visible region and generates charge carriers.

Referring to FIG. 6, there is shown an enlarged cross-sectional view ofa further embodiment of an electrophotographic photoconductor accordingto the present invention. In the embodiment, there is formed on theelectroconductive support material 1 a two-layered photosensitive layer2c comprising a charge generating layer 5 consisting essentially of thecharge generating material 3, and a charge transporting layer 6containing a styrene derivative of the previously described formula (I).

In this photoconductor, light which has passed through the chargetransporting layer 6 reaches the charge generating layer 5, so thatcharge carriers are generated within the charge generating layer 5 inthe region which the light has reached. The charge carriers which arenecessary for the light decay for latent electrostatic image formationare generated by the charge generating material 3, accepted andtransported by the charge transporting layer 6. In the chargetransporting layer 6, the styrene derivative mainly works fortransporting charge carriers. The generation and transportation of thecharge carriers are performed in the same manner as that in thephotoconductor shown in FIG. 5.

When an electrophotographic photoconductor according to the presentinvention as shown in FIG. 4 is prepared, at least one of the styrenederivatives is dispersed in a binder resin solution, and a sensitizerdye is then added to the mixture, and the thus prepared photosensitiveliquid is applied to the electroconductive support material 1 and dried,so that the photosensitive layer 2a is formed on the electroconductivesupport material 1.

It is preferable that the thickness of the photosensitive layer 2a be inthe range of about 3 μm to about 50 μm, more preferably in the range ofabout 5 μm to about 20 μm. It is preferable that the amount of thestyrene derivatives contained in the photosensitive layer 2a be in therange of about 30 wt. % to about 70 wt. % of the total weight of thephotosensitive layer 2a, more preferably about 50 wt. %. Further, it ispreferable that the amount of the sensitizer dye contained in thephotosensitive layer 2a be in the range of about 0.1 wt. % to about 5wt. % of the total weight of the photosensitive layer 2a, morepreferably in the range of about 0.5 wt. % to about 3 wt. %.

As the sensitizer dye, the following can be employed in the presentinvention: triarylmethane dyes, such as Brilliant Green, Victoria BlueB, Methyl Violet, Crystal Violet and Acid Violet 6B; xanthene dyes, suchas Rhodamine B, Rhodamine 6G, Rhodamine G Extra, Eosin S, Erythrosin,Rose Bengale and Fluorescein; thiazine dyes such as Methylene Blue;cyanin dyes such as cyanin; and pyrylium dyes, such as2,6-diphenyl-4-(N,N-dimethylaminophenyl) thiapyrylium perchlorate andbenzopyrylium salt (as described in Japanese Patent Publication48-25658). These sensitizer dyes can be used alone or in combination

An electrophotographic photoconductor according to the present inventionas shown in FIG. 5 can be prepared, for example, as follows The chargegenerating material 3 in the form of small particles is dispersed in asolution of one or more styrene derivatives and a binder agent. The thusprepared dispersion is applied to the electroconductive support material1 and is then dried, whereby the photosensitive layer 2b is formed onthe electroconductive support material 1.

It is preferable that the thickness of the photosensitive layer 2b be inthe range of about 3 μm to about 50 μm, more preferably in the range ofabout 5 μm to about 20 μm. It is preferable that the amount of thestyrene derivative contained in the photosensitive layer 2b be in therange of about 10 wt. % to about 95 wt. %, more preferably in the rangeof about 30 wt. % to about 90 wt. % of the total weight of thephotosensitive layer 2b. Further, it is preferable that the amount ofthe charge generating material 3 contained in the photosensitive layer2b be in the range of about 0.1 wt. % to about 50 wt. %, more preferablyin the range of about 1 wt. % to about 20 wt. %, of the total weight ofthe photosensitive layer 2b.

As the charge generating material 3, the following can be employed inthe present invention: inorganic pigments, such as selenium, aselenium-tellurium alloy, cadmium sulfide, a cadmium sulfide-seleniumalloy and α-silicon; and organic pigments, such as C.I. Pigment Blue 25(C.I. 21180), C.I. Pigment Red 41 (C.I. 21200), C.I. Acid Red 52 (C.I.45100) and C.I. Basic Red 3 (C.I. 45210); an azo pigment having acarbazole skeleton (Japanese Laid-Open Patent Application 53-95033), anazo dye having a distyrylbenzene skeleton (Japanese Laid-Open PatentApplication 53-133445), an azo pigment having a triphenylamine skeleton(Japanese Laid-Open Patent Application 53-132347), an azo pigment havinga dibenzothiophene skeleton (Japanese Laid-Open Patent Application54-21728), an azo pigment having an oxazole skeleton (Japanese Laid-OpenPatent Application 54-12742), an azo pigment having a fluorenon skeleton(Japanese Laid-Open Patent Application 54-22834), an azo pigment havinga bisstilbene skeleton (Japanese Laid-Open Patent Application 54-17733),an azo pigment having a distyryl oxadiazole skeleton (Japanese Laid-OpenPatent Application 54-2129), an azo dye having a distyryl carbazoleskeleton (Japanese Laid-Open Patent Application 54-14967); aphthalocyanine-type pigment such as C.I. Pigment Blue 16 (C.I. 74100);Indigo-type pigments such as C.I. Vat Brown 5 (C.I. 73410) and C.I. VatDye (C.I.73030); and perylene-type pigments, such as Algo Scarlet B(made by Bayer Co., Ltd.) and Indanthrene Scarlet R (made by Bayer Co.,Ltd.). These charge generating materials can be used alone or incombination.

The photoconductor according to the present invention as shown in FIG. 6can be prepared, for example, as follows. The charge generating material3 is vacuum-evaporated on the electroconductive support material 1, orthe charge generating material 3 in the form of fine particles isdispersed in a solution of a binder agent, the dispersion is applied tothe electroconductive support material 1 and then dried, and, ifnecessary, the applied layer is subjected to buffing to make the surfacesmooth or to adjust the thickness of the layer to a predeterminedthickness, whereby the charge generating layer 5 is formed. The chargetransporting layer 6 is then formed on the charge generating layer 5 byapplying a solution of one or more styrene derivatives and a binderagent to the charge generating layer 5 and then drying. In thisphotoconductor, the charge generating material 3 employed is the same asthat employed in the photoconductor shown in FIG. 5.

It is preferable that the thickness of the charge generating layer 5 beless than about 5 μm, more preferably less than about 2 μm. It ispreferable that the thickness of the charge transporting layer 6 be inthe range of about 3 μm to about 50 μm, more preferably in the range ofabout 5 μm to about 20 μm. In the case where the charge generating layer5 comprises the charge generating material 3 in the form of fineparticles, dispersed in a binder agent, it is preferable that the amountof the charge generating material 3 in the charge generating layer 5 bein the range of about 10 wt. % to about 95 wt. % of the entire weight ofthe charge generating layer 5, more preferably in the range of about 50wt. % to about 90 wt. %. Further, it is preferable that the amount ofthe styrene derivative contained in the charge transporting layer 6 bein the range of about 10 wt. % to about 95 wt. %, more preferably in therange of about 30 wt. % to about 90 wt. % of the total weight of thecharge transporting layer 6.

As the electroconductive support material 1 for use in the presentinvention, a metal plate or metal foil, for example, made of aluminum, aplastic film on which a metal, for example, aluminum, is evaporated, orpaper which has been treated so as to be electroconductive, can beemployed.

As the binder agent for use in the present invention, condensationresins, such as polyamide, polyurethane, polyester, epoxy resin,polyketone and polycarbonate; and vinyl polymers such aspolyvinylketone, polystyrene, poly-N-vinylcarbazole and polyacrylamide,can be used.

Other conventional electrically insulating and adhesive resins can beused as the binder agent in the present invention. When necessary, therecan be added to the binder resins a plasticizer, for example,halogenated paraffin, polybiphenyl chloride, dimethylnaphthalene anddibutyl phthalate.

In the above described photoconductors according to the presentinvention, if necessary, an adhesive layer or a barrier layer can beinterposed between the electroconductive support material and thephotosensitive layer. The adhesive layer or the barrier layer can bemade of, for example, polyamide, nitrocellulose or aluminum oxide. It ispreferable that the thickness of the adhesive layer or barrier layer beabout 1 μm or less.

When copying is performed by use of the photoconductors according to thepresent invention, the surface of the photoconductor is chargeduniformly in the dark to a predetermined polarity. The uniformly chargedphotoconductor is exposed to a light image so that a latentelectrostatic image is formed on the photoconductor. The thus formedlatent electrostatic image is developed by a developer to a visibleimage. When necessary, the developed image can be transferred to a sheetof paper. The photoconductors according to the present invention havehigh photosensitivity and excellent flexibility.

Preparation of embodiments of an electrophotographic photoconductoraccording to the present invention will now be explained in detail byreferring to the following examples.

EXAMPLE P-1

The following components were ground and dispersed in a ball mill toprepare a charge generating layer formation liquid:

    __________________________________________________________________________                                             Parts by Weight                      __________________________________________________________________________    Diane Blue (C.I. Pigment Blue 25, C.I. 21180, a charge generating             pigment)                                   76                                 of the following formula (CG-1))                                              2% tetrahydrofuran solution of a polyester resin (Vylon 200 made by           Toyobo Co., Ltd.)                        1,260                                Tetrahydrofuran                          3,700                                 ##STR680##                                                                   __________________________________________________________________________

The thus prepared charge generating layer formation liquid was appliedby a doctor blade to the aluminum-evaporated surface of analuminum-evaporated polyester base film, which served as anelectroconductive support material, so that a charge generating layerhaving a thickness of about 1 μm when dried at room temperature wasformed on the electroconductive support material.

Then the following components were mixed and dissolved, whereby a chargetransporting layer formation liquid was prepared:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Stilbene-type Derivative No. 6                                                                       2                                                      in Table 2                                                                    Polycarbonate resin (Panlite K 1300 made                                                             2                                                      by Teijin Limited.)                                                           Tetrahydrofuran        16                                                     ______________________________________                                    

The thus prepared charge transporting layer formation liquid was appliedto the aforementioned charge generating layer by a doctor blade and wasdried at 80° C. for 2 minutes and then at 105° C. for 5 minutes, so thata charge transporting layer with a thickness of about 20 μm was formedon the charge generating layer; thus, an electrophotographicphotoconductor No. 1 according to the present invention was prepared

The electrophotographic photoconductor No. 1 was charged negatively inthe dark under application of -6 kV of corona charge for 20 seconds andwas then allowed to stand in the dark for 20 seconds without applyingany charge thereto. At this moment, the surface potential Vpo (V) of thephotoconductor was measured by a Paper Analyzer (Kawaguchi ElectroWorks, Model SP-428). The photoconductor was then illuminated by atungsten lamp in such a manner that the illuminance on the illuminatedsurface of the photoconductor was 20 lux, and the exposure E_(1/2) (luxseconds) required to reduce the initial surface potential Vpo (V) to 1/2the initial surface potential Vpo (V) was measured. The results showedthat Vpo (V)=-1098 V and E_(1/2) =1.6 lux.seconds.

EXAMPLES P-2 THROUGH P-18

Example P-1 was repeated except that the charge generating material andthe charge transporting material (Stilbene-type Derivative No. 6 inTable 2) employed in Example P-1 were respectively replaced by thecharge generating materials and the charge transporting materials(stilbene-type derivatives) listed in Table 7, wherebyelectrophotographic photoconductors No. 2 through No. 18 according tothe present invention were prepared.

Vpo and E_(1/2) of the electrophotographic photoconductors No. 2 throughNo. 18 are shown in Table 8.

                                      TABLE 7                                     __________________________________________________________________________                                                            Charge                Photo-                                                  Transporting          con-                                                    Material              ductor                                                  Stilbene              No. Charge Generating Material                          Type                  __________________________________________________________________________                                                            No.                    1                                                                                 ##STR681##                                          6                     2                                                                                 ##STR682##                                         77                     3                                                                                 ##STR683##                                         22                         ##STR684##                                                                4                                                      18                     ##STR685##                                                                    5                                                                                 ##STR686##                                          2                     6                                                      65                     ##STR687##                                                                    7  CG-3                                                45                     8  CG-5                                                74                     9  CG-3                                                33                    10  CG-5                                                19                    11  CG-3                                                58                    12  CG-5                                                88                    13  CG-3                                                94                    14  CG-5                                                37                    15  CG-3                                                24                    16  CG-5                                                64                    17  CG-3                                                60                    18  CG-5                                                79                    __________________________________________________________________________

EXAMPLE P-19

Selenium was vacuum-evaporated with a thickness of approximately 1.0 μmon an appropriately 300 μm thick aluminum plate so that a chargegenerating layer was formed on the aluminum plate.

A charge transporting layer formation liquid was prepared by mixing anddispersing the following components:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Stilbene-type derivative No. 22                                                                      2                                                      in Table 2                                                                    Polyester resin (Polyester Adhesive 49000                                                            3                                                      made by Du Pont Co.)                                                          Tetrahydrofuran        45                                                     ______________________________________                                    

The thus prepared charge transporting layer formation liquid was appliedto the aforementioned selenium charge generating layer by a doctorblade, dried at room temperature and then dried under reduced pressure,so that a charge transporting layer about 10 μm thick was formed on thecharge generating layer, whereby an electrophotographic photoconductorNo. 19 according to the present invention was prepared.

Vpo and E_(1/2) were measured. The results showed that Vpo=-938 V andE_(1/2) =1.1 lux.seconds.

EXAMPLE P-20

A perylene pigment C.I. Vat Red 23 (C.I. 71130) of the following formulawas vacuum-evaporated with a thickness of about 0.3 μm on anapproximately 300 μm thick aluminum plate, whereby a charge generatinglayer was formed. ##STR688##

A charge transporting layer formation liquid was prepared by mixing anddispersing the following components:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Stilbene-type derivative No. 66                                                                      2                                                      in Table 2                                                                    Polyester resin (Polyester Adhesive 49000                                                            3                                                      made by Du Pont Co.)                                                          Tetrahydrofuran        45                                                     ______________________________________                                    

The thus prepared charge transporting layer formation liquid was appliedto the aforementioned selenium charge generating layer by a doctorblade, dried at room temperature and then dried under reduced pressure,whereby a charge transporting layer about 10 μm thick was formed on thecharge generating layer; thus an electrophotographic photoconductor No.20 according to the present invention was prepared.

Vpo and E_(1/2) were measured. The results showed that Vpo=-1250 V andE_(1/2) =1.6 lux.seconds.

EXAMPLE P-21

One part by weight of Diane Blue (C.I. Pigment Blue 25, C.I. 21180)which was the same as that employed in Example P-1 was added to 158parts by weight of tetrahydrofuran, and the mixture was ground anddispersed in a ball mill. To this mixture, 12 parts by weight ofStilbene-type styrene Derivative No. 84 and 18 parts by weight of apolyester resin (Polyester Adhesive 49000 made by Du Pont Co.) wereadded and mixed, whereby a photosensitive layer formation liquid wasprepared.

The thus prepared photosensitive layer formation liquid was applied toan aluminum-evaporated polyester film by a doctor blade and was dried at100° C. for 30 minutes, so that a photosensitive layer with a thicknessof about 16 μm was formed on the aluminum-evaporated polyester film,whereby, an electrophotographic photoconductor No. 21 according to thepresent invention was prepared

The electrophotographic photoconductor No. 21 was charged positively inthe dark under application of +6 kV of corona charge for 20 seconds andwas then allowed to stand in the dark for 20 seconds without applyingany charge thereto. At this moment, the surface potential Vpo (V) of thephotoconductor was measured by a Paper Analyzer (Kawaguchi ElectroWorks, Model SP-428). The photoconductor was then illuminated by atungsten lamp in such a manner that the illuminance on the illuminatedsurface of the photoconductor was 4.5 lux, so that the exposure E_(1/2)(lux.seconds) required to reduce the initial surface potential Vpo (V)to 1/2 the initial surface potential Vpo (V) was measured. The resultsshowed that Vpo (V)=+1206 V and E_(1/2) =1.5 lux.seconds.

The charge generating materials, the charge transporting materials,V_(po) and E_(1/2) of the electrophotographic photoconductors No. 1through No. 21 are summarized in the following Table 8:

                  TABLE 8                                                         ______________________________________                                                           Charge                                                                        Transporting                                                       Charge     Material          E.sub.1/2                                Photo-  Generating (Stilbene-Type                                                                            V.sub.po                                                                            (lux ·                          Conductor                                                                             Material   Derivative) (V)   seconds)                                 ______________________________________                                        No. 1   CG-1       No. 6       -1098 1.6                                      No. 2   CG-2       No. 77       -945 1.4                                      No. 3   CG-3       No. 33       -901 1.2                                      No. 4   CG-4       No. 18       -980 1.9                                      No. 5   CG05       No. 2        -990 0.7                                      No. 6   CG-6       No. 65       -784 0.9                                      No. 7   CG-3       No. 45       -948 1.5                                      No. 8   CG-5       No. 74      -1030 0.7                                      No. 9   CG-3       No. 33      -1240 1.4                                      No. 10  CG-5       No. 19      -1010 0.8                                      No. 11  CG-3       No. 58      -1120 1.3                                      No. 12  CG-5       No. 88       -970 0.8                                      No. 13  CG-3       No. 94       -925 0.9                                      No. 14  CG-5       No. 37      -1101 1.0                                      No. 15  CG-3       No. 24      -1240 1.5                                      No. 16  CG-5       No. 64      -1008 1.0                                      No. 17  CG-3       No. 60      -1152 1.1                                      No. 18  CG-5       No. 79      -1293 1.3                                      No. 19  selenium   No. 22       -938 1.1                                      No. 20  Perylene-type                                                                            No. 66      -1250 1.6                                              Pigment                                                               No. 21  CG-1       No. 84      +1206 1.5                                      ______________________________________                                    

EXAMPLE P-22

The following components were ground and dispersed in a ball mill toprepare a charge generating layer formation liquid:

    ______________________________________                                                           Parts by Weight                                            ______________________________________                                        Diane Blue (C.I. Pigment Blue 25,                                                                    76                                                     C.I. 21180, the charge generating                                             pigment CG-1)                                                                 2% tetrahydrofuran solution of                                                                     1,260                                                    a polyester resin (Vylon 200                                                  made by Toyobo Co., Ltd.)                                                     Tetrahydrofuran      3,700                                                    ______________________________________                                    

The thus prepared charge generating layer formation liquid was appliedby a doctor blade to the aluminum-evaporated surface of analuminum-evaporated polyester base film, which served as anelectroconductive support material, so that a charge generating layerhaving a thickness of about 1 μm when dried at room temperature wasformed on the electroconductive support material.

Then the following components were mixed and dissolved, whereby a chargetransporting layer formation liquid was prepared:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Thiophene-type Derivative No. 102                                                                    2                                                      in Table 4                                                                    Polycarbonate resin (Panlite K 1300 made                                                             2                                                      by Teijin Limited.)                                                           Tetrahydrofuran        16                                                     ______________________________________                                    

The thus prepared charge transporting layer formation liquid was appliedto the aforementioned charge generating layer by a doctor blade and wasdried at 80° C. for 2 minutes and then at 105° C. for 5 minutes, so thata charge transporting layer with a thickness of about 20 μm was formedon the charge generating layer; thus, an electrophotographicphotoconductor No. 22 according to the present invention was prepared.

Vpo and E_(1/2) were measured. The results showed that Vpo (V)=-935 Vand E_(1/2) =1.3 lux.seconds.

EXAMPLES P-23 THROUGH P-37

Example P-22 was repeated except that the charge generating material andthe charge transporting material (Thiophene-type Derivative No. 102 inTable 4) employed in Example P-22 were respectively replaced by thecharge generating materials and the charge transporting materials(thiophene-type derivatives) listed in Table 9, wherebyelectrophotographic photoconductors No. 22 through No. 37 according tothe present invention were prepared.

Vpo and E_(1/2) of the electrophotographic photoconductors No. 22through No. 37 are shown in Table 10.

                                      TABLE 9                                     __________________________________________________________________________                                                            Charge                Photo-                                                  Transporting          con-                                                    Material              ductor                                                  Thiophene             No. Charge Generating Material                          Type                  __________________________________________________________________________                                                            No.                   22                                                                                 ##STR689##                                         102                   23                                                                                 ##STR690##                                         108                   24                                                                                 ##STR691##                                         112                        ##STR692##                                                               25                                                      118                    ##STR693##                                                                   26                                                                                 ##STR694##                                         126                   27                                                      128                    ##STR695##                                                                   28  CG-3                                                132                   29  CG-5                                                116                   30  CG-3                                                 98                   31  CG-5                                                103                   32  CG-3                                                125                   33  CG-5                                                119                   34  CG-3                                                125                   35  CG-5                                                131                   36  CG-3                                                130                   37  CG-5                                                135                   __________________________________________________________________________

EXAMPLE P-38

Selenium was vacuum-evaporated with a thickness of approximately 1.0 μmon an approximately 300 μm thick aluminum plate so that a chargegenerating layer was formed on the aluminum plate.

A charge transporting layer liquid was prepared by mixing and dispersingthe following components:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Thiophene-type Derivative No. 133                                                                    2                                                      in Table 4                                                                    Polyester resin (Polyester Adhesive 49000                                                            3                                                      made by Du Pont Co.)                                                          Tetrahydrofuran        45                                                     ______________________________________                                    

The thus prepared charge transporting layer liquid was applied to theaforementioned selenium charge generating layer by a doctor blade, driedat room temperature and then dried under reduced pressure, so that acharge transporting layer about 10 μm thick was formed on the chargegenerating layer; thus, an electrophotographic photoconductor No. 38according to the present invention was prepared.

Vpo and E_(1/2) were measured. The results showed that Vpo=-681 V andE_(1/2) =0.9 lux.seconds.

EXAMPLE P-39

A perylene pigment C.I. Vat Red 23 (C.I. 71130) of the following formulawas vacuum-evaporated with a thickness of about 0 3 μm on anapproximately 300 μm thick aluminum plate so that a charge generatinglayer was formed. ##STR696##

A charge transporting layer liquid was prepared by mixing and dispersingthe following components:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Thiophene-type Derivative No. 117                                                                    2                                                      in Table 4                                                                    Polyester resin (Polyester Adhesive 49000                                                            3                                                      made by Du Pont Co.)                                                          Tetrahydrofuran        45                                                     ______________________________________                                    

The thus prepared charge transporting layer liquid was applied to theaforementioned selenium charge generating layer by a doctor blade, driedat room temperature and then dried under reduced pressure, whereby acharge transporting layer about 10 μm thick was formed on the chargegenerating layer; thus, an electrophotographic photoconductor No. 39according to the present invention was prepared.

Vpo and E_(1/2) were measured. The results showed that Vpo=-965 V andE_(1/2) =1.1 lux.seconds.

EXAMPLE P-40

One part by weight of Diane Blue (C.I. Pigment Blue 25, C.I. 21180)which was the same as that employed in Example P-1 was added to 158parts by weight of tetrahydrofuran, and the mixture was ground anddispersed in a ball mill. To this mixture, 12 parts by weight ofThiophene-type Derivative No. 107 and 18 parts by weight of a polyesterresin (Polyester Adhesive 49000 made by Du Pont Co.) were added andmixed, whereby a photosensitive layer formation liquid was prepared.

The thus prepared photosensitive layer formation liquid was applied toan aluminum-evaporated polyester film by a doctor blade and was dried at100° C. for 30 minutes, so that a photosensitive layer with a thicknessof about 16 μm was formed on the aluminum-evaporated polyester film,whereby, an electrophotographic photoconductor No. 40 according to thepresent invention was prepared.

The electrophotographic photoconductor No. 40 was charged positively inthe dark under application of +6 kV of corona charge, and Vpo andE_(1/2) of this photoconductor were measured in the same manner as inExample P-21. The results showed that Vpo (V)=+892 V and E_(1/2) =1.2lux.seconds.

The charge generating material, the charge transporting material, V_(po)and E_(1/2) of each of the electrophotographic photoconductors No. 22through No. 40 are summarized in the following Table 10:

                  TABLE 10                                                        ______________________________________                                                           Charge                                                                        Transporting                                                       Charge     Material          E.sub.1/2                                Photo-  Generating (Stilbene-Type                                                                            V.sub.po                                                                            (lux ·                          Conductor                                                                             Material   Derivative) (V)   seconds)                                 ______________________________________                                        No. 22  CG-1       No. 102     -935  1.3                                      No. 23  CG-2       No. 108     -783  1.2                                      No. 24  CG-3       No. 112     -832  1.2                                      No. 25  CG-4       No. 118     -691  0.9                                      No. 26  CG-5       No. 126     -1100 0.8                                      No. 27  CG-6       No. 128     -1376 1.3                                      No. 28  CG-3       No. 132     -1240 1.3                                      No. 29  CG-5       No. 116     -1011 1.4                                      No. 30  CG-3       No. 98      -1170 1.1                                      No. 31  CG-5       No. 103     -990  0.7                                      No. 32  CG-3       No. 124     -1265 1.3                                      No. 33  CG-5       No. 119     -1030 1.1                                      No. 34  CG-3       No. 125     -934  1.1                                      No. 35  CG-5       No. 131     -882  0.9                                      No. 36  CG-3       No. 130     -1033 1.0                                      No. 37  CG-5       No. 135     -1280 1.2                                      No. 38  Selenium   No. 133     -681  0.9                                      No. 39  Perylene-type                                                                            No. 117     -965  1.1                                              Pigment                                                               No. 40  CG-1       No. 107     +892  1.2                                      ______________________________________                                    

EXAMPLE P-41

The following components were ground and dispersed in a ball mill toprepare a charge generating layer formation liquid:

    ______________________________________                                                           Parts by Weight                                            ______________________________________                                        Diane Blue (C.I. Pigment Blue 25,                                                                    76                                                     C.I. 21180, the charge generating                                             pigment CG-1)                                                                 2% tetrahydrofuran solution of                                                                     1,260                                                    a polyester resin (Vylon 200                                                  made by Toyobo Co., Ltd.)                                                     Tetrahydrofuran      3,700                                                    ______________________________________                                    

The thus prepared charge generating layer formation liquid was appliedby a doctor blade to the aluminun-evaporated surface of analuminum-evaporated polyester base film, which served as anelectroconductive support material, so that a charge generating layerhaving a thickness of about 1 μm when dried at room temperature wasformed on the electroconductive support material.

Then the following components were mixed and dissolved, whereby a chargetransporting layer formation liquid was prepared:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Naphtharene-type Derivative No. 147                                                                  2                                                      in Table 6                                                                    Polycarbonate resin (Panlite K 1300 made                                                             2                                                      by Teijin Limited.)                                                           Tetrahydrofuran        16                                                     ______________________________________                                    

The thus prepared charge transporting layer formation liquid was appliedto the aforementioned charge generating layer by a doctor blade and wasdried at 80° C. for 2 minutes and then at 105° C. for 5 minutes, so thata charge transporting layer with a thickness of about 20 μm was formedon the charge generating layer, whereby an electrophotographicphotoconductor No. 41 according to the present invention was prepared.

Vpo and E_(1/2) of the electrophotographic photoconductor No. 41 weremeasured. The results showed that Vpo (V)=-1120 V and E_(1/2) =2.0lux.seconds.

EXAMPLES P-42 THROUGH P-58

Example P-41 was repeated except that the charge generating material andthe charge transporting material (Naphthalene-type Derivative No. 147 inTable 6) employed in Example P-41 were respectively replaced by thecharge generating materials and the charge transporting materials(naphthalene-type derivatives) listed in Table 11, wherebyelectrophotographic photoconductors No. 42 through No. 58 according tothe present invention were prepared.

Vpo and E_(1/2) of the electrophotographic photoconductors No. 42through No. 58 are shown in Table 12.

                                      TABLE 11                                    __________________________________________________________________________                                                            Charge                Photo-                                                  Transporting          con-                                                    Material              ductor                                                  Naphthalene           No. Charge Generating Material                          Type                  __________________________________________________________________________                                                            No.                   41                                                                                 ##STR697##                                         145                   42                                                                                 ##STR698##                                         147                   43                                                                                 ##STR699##                                         182                        ##STR700##                                                               44                                                      163                    ##STR701##                                                                   45                                                                                 ##STR702##                                         205                   46                                                      199                    ##STR703##                                                                   47  CG-3                                                143                   48  CG-5                                                170                   49  CG-3                                                195                   50  CG-5                                                159                   51  CG-3                                                149                   52  CG-5                                                174                   53  CG-3                                                161                   54  CG-5                                                172                   55  CG-3                                                200                   56  CG-5                                                187                   57  CG-3                                                158                   58  CG-5                                                153                   __________________________________________________________________________

EXAMPLE. P-59

Selenium was vacuum-evaporated with a thickness of approximately 1.0 μmon an approximately 300 μm thick aluminum plate so that a chargegenerating layer was formed on the aluminum plate.

A charge transporting layer liquid was prepared by mixing and dispersingthe following components:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Naphthalene-type derivative No. 162                                                                  2                                                      in Table 6                                                                    Polyester resin (Polyester Adhesive 49000                                                            3                                                      made by Du Pont Co.)                                                          Tetrahydrofuran        45                                                     ______________________________________                                    

The thus prepared charge transporting layer liquid was applied to theaforementioned selenium charge generating layer by a doctor blade, driedat room temperature and then dried under reduced pressure, so that acharge transporting layer about 10 μm thick was formed on the chargegenerating layer, whereby an electrophotographic photoconductor No. 59according to the present invention was prepared.

Vpo and E_(1/2) were measured. The results showed that Vpo=-834 V andE_(1/2) =1.4 lux.seconds.

EXAMPLE P-60

A perylene pigment C.I. Vat Red 23 (C.I. 71130) of the following formulawas vacuum-evaporated with a thickness of about 0 3 μm on anapproximately 300 μm thick aluminum plate so that a charge generatinglayer was formed. ##STR704##

A charge transporting layer liquid was prepared by mixing and dispersingthe following components:

    ______________________________________                                                             Parts by Weight                                          ______________________________________                                        Naphthalene-type Derivative No. 153                                                                  2                                                      in Table 6                                                                    Polyester resin (Polyester Adhesive 49000                                                            3                                                      made by Du Pont Co.)                                                          Tetrahydrofuran        45                                                     ______________________________________                                    

The thus prepared charge transporting layer liquid was applied to theaforementioned selenium charge generating layer by a doctor blade, driedat room temperature and then dried under reduced pressure, whereby acharge transporting layer about 10 μm thick was formed on the chargegenerating layer; thus, an electrophotographic photoconductor No. 20according to the present invention was prepared.

Vpo and E_(1/2) were measured. The results showed that Vpo=-961 V andE_(1/2) =1.3 lux.seconds.

EXAMPLE P-61

One part by weight of Diane Blue (C.I. Pigment Blue 25, C.I. 21180)which was the same as that employed in Example P-1 was added to 158parts by weight of tetrahydrofuran, and the mixture was ground anddispersed in a ball mill. To this mixture, 12 parts by weight ofNaphthalene-type styrene Derivative No. 190 and 18 parts by weight of apolyester resin (Polyester Adhesive 49000 made by Du Pont Co.) wereadded and mixed, whereby a photosensitive layer formation liquid wasprepared.

The thus prepared photosensitive layer formation liquid was applied toan aluminum-evaporated polyester film by a doctor blade and was dried at100° C. for 30 minutes, so that a photosensitive layer with a thicknessof about 16 μm was formed on the aluminum-evaporated polyester film,whereby, an electrophotographic photoconductor No. 61 according to thepresent invention was prepared.

The electrophotographic photoconductor No. 61 was charged positively inthe dark under application of +6 kV of corona charge, and Vpo andE_(1/2) of this photoconductor were measured in the same manner as inExample P-21. The results showed that Vpo (V)=+1206 V and V_(1/2) =1.5lux.seconds.

The charge generating material, the charge transporting material, V_(po)and E_(1/2) of each of the electrophotographic photoconductors No. 41through No. 61 are summarized in the following Table 12:

                  TABLE 12                                                        ______________________________________                                                          Charge                                                                        Transporting                                                Photo- Charge     Material            E.sub.1/2                               Conduc-                                                                              Generating (Naphthalene-Type                                                                           V.sub.po                                                                            (lux ·                         tor    Material   Derivative)   (V)   seconds)                                ______________________________________                                        No. 41 CG-1       No. 145       -1120 2.0                                     No. 42 CG-2       No. 147       -1002 2.4                                     No. 43 CG-3       No. 182       -1050 1.4                                     No. 44 CG-4       No. 163       -1218 1.9                                     No. 45 CG-5       No. 205        -931 1.2                                     No. 46 CG-6       No. 199       -1159 1.5                                     No. 47 CG-3       No. 143       -1080 0.9                                     No. 48 CG-5       No. 170       -1100 1.0                                     No. 49 CG-3       No. 195        -985 1.1                                     No. 50 CG-5       No. 159       -1025 0.7                                     No. 51 CG-3       No. 149       -1110 1.1                                     No. 52 CG-5       No. 174       -1020 0.9                                     No. 53 CG-3       No. 161        -896 1.0                                     No. 54 CG-5       No. 172        -980 1.3                                     No. 55 CG-3       No. 200       -1421 1.7                                     No. 56 CG-5       No. 187       -1433 1.1                                     No. 57 CG-3       No. 158       -1011 1.6                                     No. 58 CG-5       No. 153        -997 1.0                                     No. 59 Selenium   No. 162        -834 1.4                                     No. 60 Perylene-type                                                                            No. 153        -961 1.6                                            Pigment                                                                No. 61 CG-1       No. 190       +1136 1.9                                     ______________________________________                                    

Each of the electrophotographic photoconductors prepared in Example P-1through P-20, P-22 through P-39, and P-41 through P-60 was negativelycharged, while the electrophotographic photoconductors prepared inExamples P-21, P-40 and P-61 were positively charged, by a commerciallyavailable copying machine, so that a latent electrostatic image wasformed on each photoconductor and electrostatic image was formed on eachphotoconductor and was developed with a dry type developer. Thedeveloped images were transferred to a high quality transfer sheet andwere fixed to the transfer sheet. As a result, clear images wereobtained from each of the electrophotographic photoconductors.

When a wet type developer was used instead of the dry type developer, aclear image was also obtained from each of the electrophotographicphotoconductors.

What is claimed is:
 1. A styrene derivative of the formula: ##STR705##wherein A is selected from the group consisting of: ##STR706## whereinR² and R³ each represent a lower alkyl group, an aralkyl group or anunsubstituted or substituted phenyl group, with the provision that atleast one of R² and R³ is an aralkyl group, or an unsubstituted orsubstituted phenyl group; Ar is an unsubstituted or substituted phenylgroup, or an unsubstituted or substituted styryl group; and R ishydrogen, a lower alkyl group, or an unsubstituted or substituted phenylgroup, the substituent on said substituted phenyl group or substitutedstyryl group or R², R³, Ar and R being selected from the groupconsisting of alkyl, alkoxy, aryloxy, aralkyloxy, thioalkoxy,thiophenyl, halogen, dialkylamino, hydroxy, acyl, carboxy, carboxyester, trifluoromethyl, nitro and cyano.
 2. A styrene derivative asclaimed in claim 1, which is2-N,N-ditolylamino-5-β-phenylstyryl)thiophene.
 3. A styrene derivativeas claimed in claim 1, which is1-(β-phenylstyryl)-4-N,N-diphenylaminonaphthalene.